KVM: Move main vcpu loop into subarch independent code

This simplifies adding new code as well as reducing overall code size.

Signed-off-by: Avi Kivity <avi@qumranet.com>

diff --cc drivers/kvm/kvm.h
Simple merge

diff --cc drivers/kvm/kvm_main.c
Simple merge

diff --cc drivers/kvm/svm.c
Simple merge

diff --cc drivers/kvm/vmx.c
Simple merge